Lobbyists and surrogates for some of the world’s largest companies had a go-to strategy when they saw no other path to head off a damaging policy from President Trump: call Susie Wiles.

Throughout her tenure, Trump’s departing chief of staff became a sounding board for corporations and advocacy groups trying to influence the administration, according to people familiar with the matter. Her departure, announced Friday, will leave many businesses searching for a new interlocutor within the White House.

Leading Wall Street executives have often turned to Wiles and her staff. JPMorgan CEO Jamie Dimon and his team have been in regular contact with her, as well as her former deputy, James Blair, the Journal has reported. Citigroup CEO Jane Fraser has also had some interactions with both Wiles and incoming chief of staff Stephen Miller, according to people familiar with the matter.

It was Wiles, along with Vice President JD Vance, who helped broker a truce between Trump and Elon Musk after their public falling out. Musk recently poured roughly $500 million into Republican midterm efforts.

Wiles was known to encourage companies to invest domestically. After a foreign auto manufacturer announced a new plant was being built in the U.S. earlier this year, Wiles texted “thank you” to officials at the company, according to a person who received the text message.

But while Wiles was viewed as a sympathetic ear by corporate titans, their entreaties to her sometimes failed. Shortly after Trump imposed sweeping tariffs last year, a healthcare trade group reached out to Wiles and advocated for the administration to pare back the trade levies, according to a person with direct knowledge of the matter. The tariffs continued despite the lobbying effort, the person said.

White House spokeswoman Danielle Alvarez said that both Wiles and Miller have “tremendous” relationships.

“This administration will continue building powerful partnerships, advancing the president’s America First agenda, and delivering historic wins for the American people,” Alvarez said.

Wiles didn’t return requests for comment.

A Florida native, Wiles has been the president’s top aide since 2021 and was the first woman to serve as White House chief of staff. She gained Trump’s trust by working for him in 2016 and helping to win Florida, and she served as Trump’s campaign manager in 2024.

She has been one of the most influential voices on foreign and domestic policy decisions during Trump’s second term and has tried to create a less chaotic climate inside the White House compared with Trump’s first term.

Wiles in a statement on X said that Friday would be her last day. She wrote that serving the president “has been the honor of a lifetime” and said that while her role may be changing, her “commitment to the President and the mission never will.” Trump said that Wiles will move to his political operations.

Critics of Wiles say that she and other officials sometimes gave priority to business relationships for political purposes over completing the president’s agenda.

“They would often say that we can’t do certain things because that would hurt special interest configurations for the midterms,” Calley Means, a former senior adviser to Health Secretary Robert F. Kennedy Jr., said of Wiles and her allies during a Joe Rogan podcast published Friday.

Means accused Wiles of succumbing to pressure from lobbyists to stall efforts to make food healthier for children and said her team supported relaxed standards on fruit-flavored nicotine products, a top industry priority. “Susie said to me many times: ‘We need money for the midterms, Calley. We need money for the midterms,’” Means said on the podcast.

Wiles, 69, held on to her job far longer than her predecessors during Trump’s first term. She has a deep bench of contacts in Republican circles, both in Washington and in Florida, where she spent years as a political power broker.

She worked as a lobbyist at Ballard Partners, a Florida-based firm that has become among the best-connected lobbying shops in Washington under the Trump administration. The firm was founded by Brian Ballard, one of Trump’s top donors in the 2024 presidential campaign, who has reaped rewards from his access to the White House.

CEOs might not find as sympathetic an ear in Miller. He is known to be publicly combative with his enemies and hasn’t always had friendly ties to businesses.

America First Legal Foundation, a nonprofit group Miller founded, has previously filed complaints against corporations, including Nike and Disney, with the Equal Employment Opportunity Commission alleging discrimination in hiring practices.

Miller has also been adamant about supporting two policies that may affect business: the president’s aggressive immigration agenda and his tariff regime.

After Trump’s initial round of tariffs last year, Miller said at a press conference the administration wasn’t going to provide middle-class tariff relief but instead tax cuts that Trump signed into law months later.

Wiles has espoused more moderate views on immigration than Miller and often wanted the administration to temper some of its more drastic moves. Her influence increasingly irritated people on the hard right, who called for her ouster. Some of her critics had shared information with the president alleging that people close to Wiles were making money off him, according to people familiar with the matter.

Write to Brian Schwartz at brian.schwartz@wsj.com